Why does my screen go black during calls?

I own and operate my own cell phone repair biz and need to figure this issue out asap for my customer. I've now had this happen to a couple customers phones.

The screen (LCD/Dig/frame) was replaced due to a broken screen. Went great till you turn it on and make a call and the screen goes completely black and doesnt turn back on till the other person hangs up. Not even hitting the lockor power or volume will get it to come back up. I've swapped out the proximity sensor with 2 or 3 new ones with no luck but I dont really think its that. Cuz when I cover the top front of the screen with my hand/finger the screen does dim! So the sensor is working. Front facing camera was replaced as well.

The customer immediately stopped using it after the screen broke so I dont know if this is caused by drop damage or if its something else.

PLEASE...I really need (the correct) solution for this issue ASAP!!

I don't see any physical damage anywhere on any components or motherboard and I know there is no historyof water damage.

Please if you reply to this, first, I thank you, but secondly, can you please NOT leave comments like "take it to a Verizon Store" or "its junk" or bring it to a repair person"...... (well dont even comment then lol!)

I KNOW there is a FIX for this, even if ts something im just completely forgetting or overlooking, mention it, I'm human:-)

I've tried with the rubber gasket in place and without the rubber gasket..... And tried the sensors for the D800 model even and they ALL react the same.

The customer also told me tonight now that when it's dark out or when he's in a dark room (pitch black) that the screen won't come on either.... Ugh. Is it possible it's the new screen at the little windows/holes for the sensors are off or to dark?

Thanks for the reply Scott! And yes, it was the proximity sensor...apparently perhaps due to buying a cheaper after market non oem screen with a poorly aligned sensor mask. I ended up unplugging the proximity sensor (which I really don't see the need for in the first place) and the phone works perfect now. I actually prefer the phone without the proximity sensor and can easily toggle the screen manually as needed rather than the screen always being blacked out at the most inopportune times. Better than new!

15 Ответов

I experienced this issue when I replaced the frame on my phone and had to transfer everything over. The proximity sensor wasn't close enough to the glass onto the new screen so I placed a folded piece of paper between the sensor and the black piece that screws down. Make sure you place the rubber piece in the frame before installing the proximity sensor. I installed a program called sensor kinetics to see if the proximity sensor was working properly. I hope this helps! It took me a couple hours of troubleshooting to come up with a solution. The issue is that the proximity sensor wasn't close enough to the screen and I believe it was reflecting off the glass and getting a false reading. Download that program and scroll down to the proximity sensor. It will either read 5CM or 0CM. Mine was always reading 0CM. Something else to note: if you unplug the sensor with the phone on, you will need to reboot the phone to get a reading in the program.

Scott, thanks so much. A piece of paper over the proximity sensor worked. After I had my screen replaced, I was stuck with the blank screen during phone calls, with the only solution at the time being to disconnect the proximity sensor. I now followed your advice to add the piece of paper over the sensor and it's now working perfect.

I wish I could post a picture. The tiny folded piece of paper goes between that top black frame piece and the proximity sensor. The reason it works is because it applies more pressure to the sensor and pushes it closer to the screen.

He's saying check your old frame (assuming your LCD came with a new one) for a small rubber piece with two holes where your proximity sensor used to sit. Put this rubber piece in the new frame, and your proximity sensor will sit tight in it and work normally again.

I have just sorted one of these out. We replaced a full display and after a couple of weeks customer got in touch to say the double tap on function did not work and when on a phone call, the screen would not illuminate when removed from ear until the other person hung up.

Proximity sensor covers these issues.

There was an very slight gap between the rubber proximity sensor seal and the screen glass, gently pushed the rubber seal onto the glass, reinstalled the sensor and put a small bit of card over the top of the sensor before putting the black plastic cover back onto the top circuit board.

Result, sensor works great on calls and double tap works both to wake and switch screen off

That's what I did, but it requires the phone to be rooted and Xposed to be installed. The proximity sensor doesn't work anymore, but I don't really care since I can manually turn off the screen when necessary.

2) Go to Settings > Accessibility > Power button ends call

3) Use a Bluetooth headset/device to end the call

The last two options don't help with the black screen during the call, but they give you control to end it.

i fixed mine that is how : take the back cover off and tighten the small screw on the left of the back just behind the cam and sensor. wallah its all done and the screen turn off and on in less than a second. good luck .

For the LG G2, the problem is actually pretty simple. Don't install the proximity sensor while it's still on the black retaining bracket. If you leave the sensor in the bracket, and push it down far enough for the bracket to click into place, the rubber gasket prevents the actual sensor from going in as far as it should. So:

Step 1: Remove the sensor flex from the black retention bracket.

Step 2: Install the sensor into the gasket. Now that there's no bracket, you can see it go all the way to the bottom of the rubber gasket.

Step 3: Install the retention bracket.

Step 4: Put the sticky (taped) back part of the flex back onto the bracket.

Step 5: Install logic board and test for functionality.

Ever since I started doing this, I have much less problems with the prox sensors on the G2. There are still occasional problems, but it's usually just because the prox sensors LG put in the G2 are junk, and break easily.

here is what you do , i had same problem I just opened back cover and tightened the small screw behind the sensor and worked better than when i bought it knew . the screw get loose when dropped and the screen gets raised up and block part of sensor and and light do not get to sensor . try it, it worked for me like charm for me . the sensor works better than when i bought it , the phone sensor responds in less than a second. good luck.

You're missing the little rubber piece that separates the two sensors (presumably requires two separate light inputs to determine distance) that sits underneath the proximity sensor and against the screen. Look for the rubber piece (if you just replaced your screen) and put it back in, and you're golden. The problem isn't with the screen not being designed right, it's that you're missing the rubber piece that does the job of splitting the light sources.

Hi this is ted the real reason it goes the screen goes black is that all new phones are built to to have the camera lens come on and snap a photo. Of the user when you use the phone if you cover or tape the camera lens the phone wont work right.like i saidthe phone makers are require by the gov. To do this that way if someone or you calls a terrorist or lest say a terrorist act they will have a photo of that person so dont cover your lenz or it wont WORK properly